1. Field of the Invention
The present invention relates to a method of and an apparatus for finishing or treating a pair of elongate slide fastener stringers before being cut off into individual slide fastener lengths.
2. Prior Art
There have heretofore been known various methods of treating or finishing slide fastener stringers or stringer tapes so that they will be free of fraying or ravelling at cut edges after they are cut off into individual slide fastener lengths. For example, it has been customary to apply films of synthetic resin to the stringer tapes or to impregrate the tapes with a solution of synthetic resin where they are to be cut off, before severance. Such procedural step must be carried out independently of the other process steps, and hence renders the overall process more complicated, time-consuming, and less productive of finished fastener products per unit time. Another conventional practice for producing fraying-free tape edges is to cut off the stringer tapes with a heated or ultrasonically vibrated blade for fusing cut edges at the same time as the tapes are severed. This procedure is disadvantageous in that the blade must be held in its actuated position until the cut edges of the tapes become completely fused and made fraying-free. It is also time-consuming and thus results in a reduced rate of productivity.